The text is the same regarding open class revolvers and distinguished revolvers, as far as "if the trigger is capable of single action it must be capable of lifting 2.5 pounds when the gun is cocked for single action firing". If this is the case, than any revolver that is not capable of single action would have had the cocking notch removed, right? I don't know of any make that came DAO, cataloged anyway. To take it a step further, the new rule 3.1 "Applies to all firearms", states "Internal modifications that would render the firearm less safe than originally designed by the manufacture". If it can be done to a open class revolver, it must be okay for a distinguished revolver. Removing the cocking notch doesn't in anyway render the gun less safe, if it did, than we have a lot unsafe open guns, wouldn't we? Anyway, if one reads the new rules in their entirety, they would come to the conclusion that single action is no longer required for a distinguished revolver.